Gas burner orifice

ABSTRACT

An orifice device for gas burner apparatus includes a gas outlet port or orifice and an emission control so disposed in relation to the orifice as to facilitate a mixing of air with the discharged gas into a combustible mixture.

United States Patent 3,913,846 Morris Oct. 21, 1975 [5 GAS BURNER ORIFICE 664,595 12/1900 Trendel 431/354 1,095,280 5/1914 K 11 239/597 [75] Inventor: 1 Garden Grove, 1,942,783 1/1934 Tzlliii adge 138/44 Calm 2,493,209 1/1950 Simmons 239/597 x Assigneez Robertshaw Controls p y 2,513,527 7/1950 Schafer 239/4195 Rlchmond FOREIGN PATENTS OR APPLICATIONS [22] Filed: Jan. 21, 1974 1,090,002 10/1954 France 239/597 959,978 6/1964 United KingdOm.... 239/601 [211 APPL 435,628 216,170 5/1968 U.S.S.R 239/597 Related U.S. Application Data [63] Continuation of Set. N0. 201,012, Nov. 22, 1971, Primary Examiner- M. Henson Woo J abandoned. Assistant ExaminerAndres Kashnikow Attorney, Agent, or FirmAnthony A. OBrien [52] U.S. Cl. 239/597; 138/44; 239/601; 1

431/354 57 ABSTRACT 51 1111. cm B0513 1/00; F23D 13/26 1 v Field of Search 239/4195, An orifice device for gas burner apparatus includes a /5 138/44, 45, 45 A; gas outlet port or orifice and an emission control so 1 137/592; 431/354; 48/180 R, 180 B disposed in relation to the orifice as to facilitate a mixing of air with the discharged gas into a combustible [56] References Cited mixture.

UNITED STATES PATENTS 3 Claims, 4 Drawing Figures 94,103 8/1869 Glll 239/597 X US. Patent Oct. 21, 1975 FIG. 2 44 FIG. l

GAS BURNER ORIFICE CROSS REFERENCE TO RELATED APPLICATION This is a continuation of application Ser. No. 201,012 filed Nov. 22, 1971, now abandoned.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to gas burner apparatus and in particular to an orifice device for such burner apparatus.

2. Description of the Prior Art A wide variety of orifice designs have been suggested in the prior art for gas burner apparatus and for various other purposes. U.S. Pat. No. 2,450,790, No. 2,741,302, No. 3,155,143, No. 3,467,316, No. 3,469,794, and No. 3,516,771 are representative of prior art gas burners particularly designed with orifice devices having specifically shaped orifices but these devices are for liquids, such as water, and are particularly designed to function as spray nozzles such as used on water hoses and the like.

In the manufacture and design of gas burning apparatus for gas consumption devices, such as furnaces, boilers, and water heaters and the like, considerable effort has been directed to development of pilot gas burners for maintaining a pilot flame and to main gas burners for maintaining a main flame. Such pilot gas burners and main gas burners are generally classified as aerated burners where primary air is mixed with gas upstream of the burner ports so that an air-gas mixture issues from such ports, and as non-aerated burners where no primary air is utilized and merely the gas issues from the ports. In both aerated and non-aerated burners, the air-gas and the gas, respectively, are combined with secondary air after issuing from the burner ports, which secondary air is necessary for combustion purposes.

In the past, the performance of gas burners has been improved by utilizing a particular shape, e.g., square or rectangular, for each burner orifice, by utilizing tabs or Another object of this invention is to cause turbulence of gas being discharged from the outlet orifice of a gas burner apparatus.

1 The present invention has another object in that the orifice device of a gas burner is provided with projection elements downstream of the outlet for such device.

'A further object of the present invention is to construct an orifice device for gas burner apparatus with control projection downstream of and adjacent the outlet of such device in order to obtain a stable blue flame.

Other objects and advantages of the present inven-' tion will become apparent from the following description taken in conjunction with the accompanying drawmg.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is an elevation view with parts in section of burner apparatus embodying an orifice device of the present invention;

FIG. 2 is an enlarged cross section view of the orifice device in FIG. 1;

FIG. 3 is a top plan view of FIG. 2; and

FIG. 4 is a partial isometric view on an enlarged scale of a modified detail of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT tube 12 is rigidly secured to the flange 20 of a mounting baffles upstream of or directly in the orifice, and by utilizing multiple opposing orifices as a substitute for a single orifice. While such prior art gas burners may have been satisfactory for their particular requirements, they were accompanied with disadvantages, such as flame distortion and high manufacturing costs; in addition, none of them provided a final solution in the quest for a stable blue flame issuing from a gas burner orifice. The problem involved in obtaining a stable flame, particularly at elevated orifice temperatures and/or lower gas inlet pressures, has not been solved because, as evidenced by the prior art devices, the problem was considered to be associated with the gas stream prior to its issuance from the burner orifice.

SUMMARY OF THE INVENTION The present invention is summarized in that an orifice device for gas burner apparatus includes a generally hollow body having an inlet adapted to be connected to a gas source, orifice means defining outlet means from the hollow body, and emission control means disposed downstream of the orifice means to enhance air mixture with the gas being discharged from the orifice means.

It is an object of the present invention to control the gas being discharged from the outlet orifice of a gas burner apparatus.

socket 22 which is suitably attached to or integral with a mounting bracket (not shown). The lower exterior of the mounting socket 20 is threaded to engage the internal threads of a compression nut 24$ a compression fitting in the form of a ball-type sleeve 26 is fitted on the upper end of a gas supply pipe 28. Oppositely inclined sections on the exterior of the sleeve 26 are wedged by a complementary inclined section on the coupling nut 24 to retain the gas supply pipe 28 in assembled relation.

All of the above described structure is conventional and for a more detailed description of such structure and its operation, reference is made to the above mentioned U.S. Pat. No. 3,155,143.

An orifice device, indicated generally at 30, has a generally hollow configuration with one orificed end and an opposite opened end defined by a lower annular skirt 32 which is wedged by one of inclined sections on the sleeve 26 to retain the orifice device 30 in assembled relation in the mounting socket 22. As is shown in FIG. 2, the orifice device 30 includes a central cylindrical body 34 extending between the lower annular skirt 32 and an upper conical portion 36 which is truncated to define a transverse end wall 38. As is illustrated in FIGS. 3 and 4, a circular recess 40 is centrally located on the exterior surface of the endiwall 38 and a generally rectangular opening or orifice 42 is punched through the center of the recess 40. A gas discharge or emission control is adjacent the orifice 42 and is disposed on the recess 40downstream of the orifice 42. In the illustrated embodiment, the gas discharge control takes the form of a pair of tabs 44 and 46 with one on each side of the rectangular orifice 42; as best illustrated in FIGS. 2 and 4, the tabs 44 and 46 project generally perpendicularly from the recess 40 and extend a distance notexceeding the surface of end wall 38 so as to be substantially flush with such end wall surface.

In the particular arrangement shown in FIG. 2, the gas discharge control tabs 44 and 46 have a generally rectangular configuration and the orifice 42 also has a generally rectangular configuration. The control tabs 44 and 46 are aligned in parallel spaced relationship to each other and substantially perpendicular to the plane defined by thecircular recess 40. The shape of the orifice 42 and the shapes of the control tabs 44 and 46 are not necessarily correlated to each other since the orifice shape may be different from the control tab shape. Furthermore, shapes other than rectangular may be utilized for both the orifice 42 and the control tabs 44 and 46 as will be apparent to persons skilled in the art.

While the illustrated embodiment shows the use of two contol tabs 44 and 46, the specific number of such tabs may be more or less than two, such as a single control tab or three control tabs. Whatever number of control tabs are used, each such tab may be integral with the end wall 38 and the circular recess 40 therein, or

it may be manufactured as a separate component and appropriately secured to the orifice device 30 in any suitablemanner. As is illustrated in FIG. 2, the control tabs 44 and 46 do not protrude above the plane defined by the end wall38 with the resulting advantage that such control tabs are protected during bulk handling and assembly. The circular recess 40, on which the control tabs and 46 are located, is easily formed by coining; thus, in FIG. 2, the circular recess 40 is defined by the coined depression which thins out the material so as to facilitate punching. However, as is shown in FIG. 4, the end wall 38 is sufficiently thin in cross section that the recess 40 may be simply made as by deforming'the center of the end wall 38 inwardly. The punching operation not only makes the orifice 42 but also makes the control tabs 44 and 46 by being punched from the inside out as with a rectangular punch having a chisel point. With such an arrangement, the circular recess 40 not only protects the gas emission control means, such as the projecting tabs 44 and 46, but also provides a simple means for the integral formation of such tabs.

During the operation of gas burner apparatus, a source of gas (not shown) supplies a flow of gas into the skirted inlet 32 of the orifice device 30; thence the gas isdischarged from the orifice device 30 through the orifice 4'2 with a jet action as is well known in the art. The relatively high velocity gas jet discharged from prior art orifice devices is uncontrolled, i.e., free to disperse for subsequent mixing with secondary air for combustion purposes. In accordance with the present invention, the discharged gas from the orifice 42 is controlled by the emission control means, which is illustrated in the form of control tabs 44 and 46. The discharged gas is prevented from being freely dispersed but rather is confined or controlled as it passes the control tabs 44 and 46. Not only is the discharged gas controlled by the tabs 44 and 46 but it is also subject to turbulence by rubbing against such emission control means WhlCIl accordingly acts as a turbulator device.

In the particular installation shown in FIG. 1, once the discharged gas leaves thecontrol tabs 44 and 46, it passes through the air entrainment area and thence into the inner tube 14 where the entrained primary air and gas are thoroughly mixed. The increased turbulence of the discharged gas acts in a manner like eddy currents causing it to be mixed with the secondary air for combustion purposes.

The orifice device according to the present invention may be utilized as a pilot gas burner as well as being utilized at the outlet ports of a main gas burner. Furthermore, it may be used in a non-aerated burner as well as in an aerated burner. For instance, in an aerated burner, primary air is mixed with the gas upstream of the orifice outlet but in such case the mixture is then discharged through orifice 42 and is subject to control and turbulence creation by the emission control tabs 44 and 46.

In one particular test of the present invention, the orifice device 30 was assembled in a non-aerated pilot gas burner of the type illustrated in FIG. 1 and produced a stable blue flame. The stable blue flame was obtained even with a low gas inlet pressure measured at 0.5 inches of water column and with the orifice temperature measured at 700F. Thus, the orifice device 30 of the present invention exhibited immunity to temperature and pressure without changing the stable blue flame. Prior art devices produce a flame that has a yellow portion in the blue portion and the more yellow the flame the more unstable it is; in addition, the yellow part of the flame indicates incomplete combustion. By the assurance that the orifice device 30 will maintain a stable blue flame, it will be assured that complete combustion will occur.

Inasmuch as the present invention is subject to many variations, modifications and changes in detail, it is intended that all matter contained in the foregoing description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

What is claimed:

1. An orifice device for gas burner apparatus comprising a generally hollow body having opposite end portions,

an inlet in one end portion adapted to receive a flow of gas,

a wall having a generally rectangular orifice in the other end portion for discharging a flow of gas therefrom,

a pair of projecting tabs integrally formed with the wall,

said projecting tabs being located on opposite sides of said rectangular orifice with each tab being contiguously aligned with its corresponding side causing turbulence of the gas flow being discharged from said rectangular orifice, and

said projecting tabs extending transversely from the wall in a direction away from said wall and being downstream of said orifice for controlling the gas flow being discharged from said rectangular orifice in order to enhance air mixture therewith.

2. An orifice device for gas burner apparatus comprising mounting means for connecting to a source of fuel,

a unitary hollow cylindrical body with an end wall on one end of the body,

means for securing the other end of the body to the mounting means,

said end wall havinganouter portion within a plane and having a flat circular recessed portion which is depressed from the plane of the outer portion,

said end wall further having a rectangular orifice formed in the recessed portion,

a pair of spaced rectangular tabs projecting downstream perpendicularly from the outer surface of the recessed portion,

said pair of tabs terminating such that they do not protrude beyond the plane of the outer portion of the end wall, and

said pair of tabs having parallel facing planar surfaces cessed portion. 

1. An orifice device for gas burner apparatus comprising a generally hollow body having opposite end portions, an inlet in one end portion adapted to receive a flow of gas, a wall having a generally rectangular orifice in the other end portion for discharging a flow of gas therefrom, a pair of projecting tabs integrally formed with the wall, said projecting tabs being located on opposite sides of said rectangular orifice with each tab being contiguously aligned with its corresponding side causing turbulence of the gas flow being discharged from said rectangular orifice, and said projecting tabs extending transversely from the wall in a direction away from said wall and being downstream of said orifice for controlling the gas flow being discharged from said rectangular orifice in order to enhance air mixture therewith.
 2. An orifice device for gas burner apparatus comprising mounting means for connecting to a source of fuel, a unitary hollow cylindrical body with an end wall on one end of the body, means for securing the other end of the body to the mounting means, said end wall having an outer portion within a plane and having a flat circular recessed portion which is depressed from the plane of the outer portion, said end wall further having a rectangular orifice formed in the recessed portion, a pair of spaced rectangular tabs projecting downstream perpendicularly from the outer surface of the recessed portion, said pair of tabs terminating such that they do not protrude beyond the plane of the outer portion of the end wall, and said pair of tabs having parallel facing planar surfaces contiguous with opposite parallel side surfaces of the rectangular orifice for rubbing and turbulating gas discharged from the rectangular orifice.
 3. An orifice device as claimed in claim 2 wherein the rectangular orifice is elongated with longitudinal sides and short transverse sides, the pair of tabs are integral downstream deformed portions of the longitudinal sides of the rectangular orifice, and the transverse sides of the rectangular orifice are open downstream from the outer surface of the recessed portion. 